You can use Events or a Script. With events, just change the player's graphic to the Airship graphic, increase speed, and set to Through, all of which can be done in the Move Route event command. Then create Landing Events where the ship turns back into the player, who walks one space in any direction, and then the landing event takes on the image of the ship, so as to look like it is landed and waiting for the player to use it again.
Peace of cake.